Sex and timing of gonadectomy relative to puberty interact to influence weight, body composition, and feeding behaviors in mice.

Gonadal sex steroids are important regulators of energy balance in adult rodents, and gonadectomy (GDX) has opposing effects on weight gain in sexually mature males and females. Puberty is associated with the emergence of sex differences in weight, body composition, and feeding behaviors, yet the role of gonadal hormones at puberty remains unclear. To address this, we performed GDX or sham surgery in male and female C57Bl/6 mice at postnatal day (P)25 (prepubertal) or P60 (postpubertal) timepoints and measured weight and body composition for 35 days, after which ad libitum and operant food intake was measured using Feeding Experimentation Device 3 (FED3s) in the home cage. Consistent with previous studies, postpubertal GDX caused weight gain in females and weight loss in males and increased adiposity in both sexes. However, prepubertal GDX decreased weight gain and altered body composition across the adolescent transition (P25 to P60) in males but had no effect in females. Despite the varied effects on weight, GDX decreased food intake and motivation for food as assessed in operant tasks regardless of sex or timing of surgery relative to puberty. Our findings indicate that GDX interacts with both sex and age at surgery to influence weight, body composition, and feeding behavior.

Basal cell carcinoma arising in a nevus sebaceus in a child with facial trichoepitheliomas.

Nevus sebaceus (NS) is a congenital skin hamartoma that presents in childhood. Tumors may arise within these lesions over time. Mutations in the PTCH gene have been associated with both NS and some of the developing tumors. Only nine documented cases of basal cell carcinoma arising in nevus sebaceus in childhood are available. We present a case of an 8-year-old male with nevus sebaceus who developed a basal cell carcinoma. Evaluation for constitutional PTCH gene mutation and loss of heterozygosity (LOH) from the BCC within the NS did not reveal an underlying mutation. We further discuss the literature regarding prophylactic excision of NS.